Wifi not in range

The tablet been working fine. It had this issue before and after a couple days is back to normal. Now it won't connect to my home wifi and saying it's not in range. I restarted the router, restored the tablet, turn off and on reboot. Still nothing. Need some help please.

Elite 7Q, 4.4 android version, firmware v4.5, Kernel 3.3.0, SELinux status Enforcing